feat(add): Add an "add" function (#59)

* WIP: Add an "add" function

* fix: Handled code coverage

* Made changes for additon reference

Closes #55

Author: Vali Shah

src/add.js

@@ -0,0 +1,12 @@
+export default add
+
+/**
+ * This method will perform addition operation.
+ *
+ * @param {Number} num1 - first number for addition
+ * @param {Number} num2 - second  number for additon
+ * @return {Number} - Result of addition
+ */
+function add(num1, num2) {
+  return num1 + num2
+}

src/index.js

@@ -13,6 +13,7 @@ import hex2rgb from './hex2rgb'
 import isNullOrWhitespace from './is-null-or-whitespace'
 import startsWith from './startsWith'
 import removeDuplicates from './remove-duplicates'
+import add from './add'
 
 export {
   flatten,
@@ -30,4 +31,5 @@ export {
   isNullOrWhitespace,
   startsWith,
   removeDuplicates,
+  add,
 }

test/add.test.js

@@ -0,0 +1,10 @@
+import test from 'ava'
+import {add} from '../src'
+
+test('Adds two integers ', t => {
+  const number1 = 23
+  const number2 = 3
+  const expected = 23 + 3
+  const actual = add(number1, number2)
+  t.deepEqual(actual, expected)
+})